Ayman al-Zawahri, an Egyptian physician who has been responsible for terrorist attacks in North America, Asia, Africa and the Middle East and dubbed as the "mastermind" behind 9/11, told his followers in an audio message posted to militant websites this week that they should stop antagonizing the country's Christians because "we have to be busy confronting the Americanized coup of (Gen. Abdel-Fattah) el-Sissi and establish an Islamic government instead," according to the Associated Press.

In July 2013, Egypt's military oversaw the ejection from power of then-President Mohammed Morsi, a member of the Muslim Brotherhood who was elected just a year before. Following Morsi's fall from power, Coptic Christians were made into scapegoats and targeted by Morsi-supporters after some Copt leaders had expressed their support of action against Morsi's regime.

Seeking retribution later that summer, parts of southern Egypt in the Minya province were taken over by Islamists before the government wrested back control in late September. In August, Islamists burned or destroyed more than 70 churches and religious institutions, killing four people. Two months later in October, two gunmen opened fire at a Christian wedding, killing four people.

Al-Zawahri said that the group's scapegoating of the Christian community had only hurt the image of Muslims in the West.

"We must not seek war with the Christians and thus give the West an excuse to blame Muslims, as has happened before," al-Zawahri suggested.

While al-Zawahri was critical of Morsi, who he blamed for cooperating with secular Egyptians and surrendering to "the Americans by acknowledging agreements with them and Israel," he saved his harshest vitriol for Mushir Sisi, the current Commander-in-Chief of Egypt's military.

"He is a mercenary, an Americanized puppet, an impostor, treacherous and sinful with a history of bootlicking," al-Zawahri said.

Al-Zawahri's new remarks come amid his recent call for unity among the region's Muslims. Nearly 1,400 people have died due to fighting among rebel groups in Syria, leading the al-Qaeda leader to ask the groups to come together to overthrow Syrian President Bashar al-Assad rather than fighting one another.